Stylus-bar mounting for sound-boxes



H. Y. PRENDERGAST.

STYLUS BAR MOUNTING FOR SOUND BOXES.

APPLICATION FILED MAR,26,1920- Patnted. Nov. 1, 1921.

A 0 rs UNITED s Arss earssr assist.

HAROLD YfrRnNDEneAsr, or new YORK, 1v. Y.

STYLUS-BAR MOUNTING FOR SOUND-BOXES.

.- T 0 all whom it may concern Be it known that I, HAROLD Y. PRENDER- oAs'r, a subject of the King of Great Britain, residing at New York city, borough of Brooklyn, county of Kings, and State of New York, have invented a certain new and useful Stylus-Bar Mounting" for Sound Boxes, of which the following is a specification. 7

This invention is directed to an improvement in phonographic sound boxes andparticularly to a means for. mounting the stylus I bar of such boxes to resiliently hold said stylus bar in its engagement with relation to the box. The present invention seeks to overcome the objection of having the spring mounting of the'stylus bar arranged in part, or, as is general, wholly exteriorly of the sound box casing, as by such an arrangement, the mounting is exposed'to deteriora tion, incident to atmospheric conditions, or

to disarrangement by the user from an inqu1s1t1ve point of view, and in general, from handling to'which the sound box is constantly subjected. These conditions tend to the probability of a change in the delicate adjustment and generally result in the efficiency of the mounting being impaired. The present invention overcomes these obj ections by arranging the spring mounting wholly within the interior of the sound box hereinafter also termed in the claims the sound space, and by reason'of such an arrangement a spring of suflicient size may be utilized, and when so adjusted is protected against accident or disarra-ngement; and

furthermore such spring is protected against atmospheric conditions, and by its position permits the use of a single spring which maybe so associated .with the mounting asto eliminate the use'of screws,rscrew threads, lock nuts, and the like;

- The mounting of the present invention may be associated with a sound box of-any desired form or style, but for the purpose of the present showing, I have illustrated the general type of sound box disclosed in my co-pending application, Ser. No. 175,273, filed June 18th, 1917. In the showing made,

A designates-the casing of the sound box,

which is provided with a back plate B, and

to which casing is mounted a diaphragm C.

To the center of the diaphragm is secured one end of a stylus bar D, the other end of said bar being fixed to a hub E. -Projecting from the exterior of the casing are a Specification of Letters Patent. I

a coil spring J, the other arm 7 Patented Nov. 1, 1921.

Serial No. 368,835.

pair of abutments F which may be either integralwith the casing or secured thereon in any suitable manner. The abutments F are tapered as shown to form knife edges 9 or, if desired, said abutments may be tapered :to points instead of knife edges. The hub E of the stylus bar is adapted to rest against the knife edges 9 and is provided with a socket 6 adapted to receive a stylus H secured in position by a binding screw it.

In accordance with the present invention, the hub E has ahixed thereto one end of a rod or wire I, which extends through an apertureor slot a in the wall'of said casing, to apoint interiorly of the box. The wire or rod I maybe secured to'the hub of the stylus bar in anysuitable manner, and this may be expeditiously and simply accomplished by extendingthe stylus socket entirely through the hub. Into the back end of the stylus socket, the end of the wire or rod I may be positioned and thereafter a drop of solder may be used for the purpose of soldering the end of the rod I firmly in position. For the better. security, I provide the rod- I with a head K at the end opposite the hook L of said rod to cooperate with the inner channel wall of the stylus socket. It will be seen that the passage provided in the stylus bar to receivethe rod I is smaller than the head K, so that thereby the head K will abut against the wall of the stylus socket and retain the rod I in proper posi- .tion in and relationto the stylus bar, even should the :usual solderingbe omitted or r Inthe form of the invention shown in Figs. 1 and 2, the. inner'end of the. wire or rod I is formed into a hook z and with this hook is adapted to cooperate one arm 7' of of which engages'with the. interior of the casing, as

clearly shown in Fig, 2. The end of the arm j may be bent outwardly and extend into an aperture in the casing to preclude displacement of the spring, if desired. The spring J is of the expansion type and when positioned as shown in Fig. 2 serves to exert a pull on the rod I, which serves to properly hold the hub E to a seat on the knife edges gf By positioning the spring J and stronger spring may be employed than could conveniently be used if the same were positioned exteriorly of the casing. Moreover, the rod I is preferably positioned on the hub E so as to be in direct alinement wlth the stylus H, and in lateral alinement with the knife edges 9. By this construction, a very sensitive arrangement results even though the spring-is under considerable tension. it is preferable that the hub be drawn with relatively great tension against the knife edges and this can be well accompiished by the construction illustrated without in any wise sacrificing the sensitiveness ofthe mounting to vibrations.

It is quite feasible to form a spring J integral with the wire I after the manner shown in Fig. 4:. Manifestly, other forms of springs may be associated with the stylus bar by forming the same integral therewith or separate therefrom without .departing from the spirit of this invention. If desired, the knife edges maybe formed on the hub E- and rest against the casing,

this construction being merely a reversalof the construction shown in Fig. 3.

In the foregoing description I have set forth illustratlve ways of carrying out the present invention, but I desire it to be understood that the present invention is capable of mechanical changes or equivalents,

without departing from the invention, the

same being defined and limited only by terms of the appended claims.

Having thus fully described the invention, what I claim as new and desireto secure by Letters Patent is: a

1. A sound box, a stylus bar movably engaging said box, and means arranged wholly within said box to exert a tension on said bar. I

2, A sound box, a stylus bar movably engaging said box and formed with a stylusreceiving opening, and means arranged wholly within said box and operating in line with said opening to tension said bar in its engagement with said box.

3. A sound box, a stylus bar'movably engaging said box, and a spring arranged wholly within said box to exert a tension on said bar in its engagement with said box.

' 4. A sound box, a stylus bar movably engaging said box and formed with a stylusreceiving opening, and a spring arranged Wholly within said box and operating in line with said opening to tension said bar in its engagement with said box.

having a hook.

5. A sound box having a diaphragm, and a sound space beyond the diaphragm a stylus bar movably engaging the sound box, a spring secured to the sound box and arranged wholly within the sound space thereof, and a connection between said spring and stylus bar, whereby to hold said bar under the tension of such spring.

. 6. A sound box, a stylus bar movably engaging said box, a spring element including a coil and arms projecting therefrom, one of said arms terminating in line with the stylus bar, and a connection between said arm and bar to tension the bar in its engagement with the box.,

7. A soundbox having a diaphragm and providing a sound space in advance thereof, a stylus bar movably engaging said box, a spring element arranged wholly within said sound space and including a coil, an arm projecting therefrom and bearing against a wall of the box, and a free arm terminating approximately in line with and connected to said stylus bar. I

8. A stylus bar formed with a connecting rod recess having a reduced portion, of a connecting rod having a body portion formed atone end with a head to engage the shoulder formed by the reduced portion of said recess, said rod being formed at the opposite-end with a hook.

9. A connecting rod for the stylus bar of a sound box having a body portion capable of longitudinal movement through thestylus bar, a head for cooperation with the stylus bar to limit movement of the rod in one direction, and a hook on the endof the rod opposite the head i 10. A stylus bar an opening in line with the stylus socket, a connecting bar fitting in said opening and having a head to cooperate with. the walls of the opening between the end limits of for sound boxes having said opening to limit movement of the bar in one direction,the opposite end of the rod 11. A sound box, a stylus bar thereon having a channel in linewith the stylus socket,

and a connecting rod mounted in said channel and formed with a head to cooperate with the channel wall to limit movement of 1 the rod in one direction, said rod extending through and within the sound box and being formed with a hook terminal at the end within the sound box.

In testimony whereof, I have signed my name to this specification.

- HAROLD Y. PRENDERGAST, 

